freewheel dismantling

m-gineering wrote:
Vee wrote:

David L. Johnson wrote:

But if you want to get inside the freewheel part, you are asking for
trouble. There are 3,287 little tiny bearings in there,

There's less than a hundred bearings,



Or not even that. I've opened freewheels which held only six balls and
peices of bent wire to keep them apart! Later Sachs freewheels have the
bals in a cage


I would only add: work on the

freewheel while it's held in a vise via a freewheel tool because you'll
make less of a mess and it's far easier if you can turn the freewheel
upside down.


This works with the splined type. For notch type freewheels clamp an old
hub in a vise (drop a bolt in the housing to keep it from squashing).
spin the freewheel on, it tightens when you knock the bearing ring loose
and vice versa.

Regina's were indeed hopeless to work on, but an Atom body was
dimensionally the same and took all the cogs

While we're offering actual practical advice here, here's some more
pointers to make your reassembly job easier:

Open the freewheel over a large rag. If possible, count the bearings on
each side before removal, but if not, the rag will catch them. This is
much easier than estimating how many will fit during reassembly.

SunTour New Winner freewheels require a special tool for opening the
body - they had adjustable bearings, a design that was eliminated in the
next incarnation, "Winner Pro". For all others, a screw cover with
pinholes has a left-hand thread. A drift punch will work, but a pin
tool allows more control.

Put a very thin film of grease on the bearing surfaces before
reassembly. The balls will "stick" in place. If you are worried that
the grease was enough to gum up the pawls, you can flush with WD-40
after reassembly, allow to dry, then oil - but a thin film shouldn't be
a problem.

I agree that this work isn't worth it if your time is more valuable than
your money - unless you're just curious, or have a vintage freewheel
that has some collector's value. Back when I was a college student with
more time than money, I resurrected a few friends' rusted-out freewheels
this way.

Mark

Here's another suggestion.

If you really want to catch ALL the balls, put a strong magnet inside
the rag, and/or set it all inside a shallow tub or tray when you open
the thing up.

Some will argue about the dangers of magnetizing ball bearings, but
any evil that results isn't nearly as bad as having to reassemble the
thing with one or two balls missing.

Steve W wrote:
I have a 6 speed screw on shimano freewheel set and I would like to
dismantle it. Can it be done with two chain whips or do i need a special
spanner to undo what appears to be a slim lock ring with 8 semi circular cut
outs in the outside of it.

Hold the low gear in a freewheel vise and unscrew the
lockring, ideally with a pliers-type lockring tool such as a
Var #16.

Older Shimano MF cogs can be cut to fit the mid and low gear
positions on these new freewheel bodies. There's an extra
square cutout in addition to the traditional serrated pattern.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971